Abstract: The proton form of nanosized, needlelike ferrierite zeolite, which was synthesized using choline and Na+cations as structure-directing agents, was found to be much more efficient for the skeletal isomerization of 1-butene to isobutene than the corresponding cation form of conventional, submicrometricferrierite with a platelike shape, mainly because of the considerably lower density of strong acid sites, but as well as a result of the higher density of 10-ring pore mouths.